<div class="row">
    <div class="col-xs-3">
        <img class="img-rounded" title=".img-rounded" alt=".img-rounded" src="">
    </div>
    <div class="col-xs-3">
        <img class="img-circle" title=".img-circle" alt=".img-circle" src="">
    </div>
    <div class="col-xs-3">
        <img class="img-thumbnail" title=".img-thumbnail" alt=".img-thumbnail" src="">
    </div>
    <div class="col-xs-3">
        <img class="img-responsive" title=".img-responsive" alt=".img-responsive" src="">
    </div>
</div>